Non-metallic mine fuse



J y 15, 1958 I F. LAZARI 2,843,042

. NON-METALLIC MINE FUSE Filed July 17, 1952 metallic fuze.

NON-METALLIC MINE FUSE FahriziowLaz ari, lVIilanfItaly, assignor toMontecatini,

.:Societa Generale per llndustria Mineraria e Chimica, a corporation ofItaly i s Application July1 7, 1952, Serial No. 299,305 7 Claimspriority, application Italy August 4, 1951 12 Claims. (21. 102-70 Thisinvention relates to a fuze, particularly a non- It is known that the.fuzes of antitank and antipersonnel land: mines are usually actuateddirectly by crushing caused by the weight of the object againstwhichjthe mines are directed.

' These fuzes activated by-crushing, consist essentially of a percussioncap or detonator which is struck by a firing pin when the fuze issubjected to a predetermined 'force.

7, Generally, the striker is projected against the sensitive detonatorby the force of a spring, previously compressed and held in suchcondition by a stop system which is rendered ineffective by crushing thecover of the fuze.

"In this typeof fuze, the release of the spring imparts .to the strikera uniform striking force which is always sufficient to insure firing ofthe detonator.

I' On the contrary, in other types offuzes the striker is pushed againstthe detonator directly by the impact exertedsl pon the cover of thefuze, and in this case, accordingto the circumstances, the force of theimpact may or may not be sufficient to ignite the detonator. The lastmentioned type of fuze is particularly adapted for use in nonemetallicmines, wherein metallic springs cannot be used. V

' L It is therefore an object of the present invention to p'ro'vide'awholly non-magnetic fuze, which comprises a detonator, 'a striker forigniting said detonator andwhich includes a device to insure that thestriker is actuated by a constant force of impact, independent of thedirection in which the force crushing the coveris applied.

- In particularthis effect is attained in the present in vention byreplacing the predetermined elastic force of a spring bytheelastic'forceof a compressed gas contained in a hermetically sealedcontainer. The gas container is disposed in a chamber at one end ofwhich the strikeris slidably fitted as a-piston Breakage of thecompressedgas container, upon crushing of the fuze,

exerts a pressure upon the striker and projects it against a suitablylocated percussion cap, striking it with a uniform force alwayssufiicientto ignite the detonator. The

. gas containervmay consist of a vitreous or glass ampoule, which inaddition to the required fragility offers an unexpected high resistanceto the internal pressure, in

comparison with the necessarily small thickness of the walls. The gascontainer is preferably charged with a stable gas under a pressure offrom 1 to atmospheres.

Methods of making gas conatiners suitable for use in the non-metallicland mine herein disclosed are described Metallic Fuzes, Serial No.612,177, filed September 26,

For further details of the invention reference is made v to thefollowing description and drawing, which are intended to be illustrativeand not limitative, of an emi The fuze consists of a base 1 and cap orcover 2, made of rigid material, having adequate resistance (e.'g.synthetic resin) and of a perimetral band 3 madealso from stiff materialand having a fragility adequate for the sensitivity required of thefuse. Such a band constitutes at the same time the rigid and hermeticconnection of the base with the cover and the predetermined to the baseare surrounded by a plastic material envelope 7 5 The envelope 5 affordsa gas-tight but non-rigid con-.

nection between the sockets. Inside the sockets is disposed thecompressed gas container 6 made of fragile material (e. g. glass). orglass ampule: containing a pres-fill of compressed propellant gas. v r

The internal recess, cavity or bore 7 of the socket 4' communicates withthe recess or bore in the base'of the fuse. striker 8 is located, whichoperates as a piston. The striker 8 is held in place by a thin andyieldable baflle 9, which serves to preserve the hermetic closure of thepneumatic chamber. Under the striker, the detonating means of percussioncap 10, containing the blasting fuse, is located. 1

' When the cover of the fuse is subjected to a weight v torsional ortwisting couple.

I claim:

1. A percussion fuze for non-metallic mines, comprising a percussioncap, a striker for igniting-said percussion cap,

a frangible'hermetically sealed container containing a prefill' ofcompressed propellant gas, said striker being disposedin strikingposition between said container and said percussion cap, and enclosuremeans surrounding said. container and said striker sa id enclosure meansbeing. operative, upon impact thereupon, to break said frangiblecontainer, whereby said striker will be propelled by the kinetic energyof the released gas to strike upon and ignite said percussion cap. i

2. .A percussion fuze fornon-metallic mines compris ing a percussioncap, a striker for igniting said percus-p sion cap, a frangiblehermetically sealed container con- .bodiment of a fuze according to thepresent invention.

taining a pre-fill of compressed propellant gas,' .said striker: beingdisposed in striking position between said container and said percussioncap, and enclosure means surrounding said container and said striker,said enclosure means-beingoperative, upon impact thereupon, l

to break said frangible container, whereby said striker will bepropelled by the kinetic energy of the released gas to strike upon andignite said percussion cap, said enclosure means comprising a basemember and a cap member, means for holding said base and cap members inspaced relation, a first recess in said base member, said striker beingslidably disposed in said first'bore, a second recess in said capmember, said container being disposed in embracing relationship withinsaid first and second recesses and intermediate said base and capmembers. 7

3. The invention as defined in claim 2 including frangi- Patented Jul'15, 1958] The container 6 comprises a vitreous Within the bore at aconvenient height the container as a ble baffie means for sealing saidstriker in said first bore prior to fracture of said frangiblecontainer.

4. The invention as defined in claim 2 wherein said base and said capare provided with coaxial cylindrical surfaces, and including a stiff,cylindrical band fixed between said surfaces to hold said base and capin-spaced coaxial alignment, said band being of predetermined fragilitywhereby an impact of certain force will distort it and allow thebase andcap to be moved relative each other to fracture the gas container.

5. The invention as defined in claim 2 wherein said holding. andenclosure means comprises a resilient cylindrical sleeve, and a pair ofcomplementary coaxial cylindrical shoulders surrounding said first andsecond bores, said sleeve being hermetically sealed against saidshoulders.

6. The inventionas defined in claim 2 wherein said cap is archedupwardly, whereby impacts upon the side thereof will result in forcesacting as a torsion couple upon said gas container.

7. A springless non-metallic percussion fuze for land mines comprising apercussion cap, a firing striker for the percussion cap, a frangiblehermetically sealed container containing a pre-fill of compressedpropellant gas, the striker being positioned between said container andthe percussion cap, enclosure means surrounding said sealed containerand said striker, said enclosure means.

providingv a base, an impact cap, and a lateral gas retaining wallconnecting the base and impact cap, im pact upon the cap serving tobreak the frangible container to release the compressed gas, thereleased gas being confined within the enclosure means and against thestriker, whereby the striker is propelled by the force of the gas tostrike upon the percussion cap, the gas imparting to the striker akinetic energy sufficient for.

ignition.

8. The apparatus defined in claim 7, the impact cap having an outersurface which is arched at its periphery, to augment twisting andbreaking action on the sealed container imparted by a laterally directedimpact force.

9. A non-metallic percussion fuze for land mines comprising: apercussion cap; a firing striker for the percussion cap; a frangiblehermetically sealed vitreous ampule containing compressed gas; thestriker being positioned between said ampule and the percussion cap;enclosure means surrounding said ampule and said striker, said enclosuremeans providing a base structure having a recess, an impact cap having arecess, and a lateral gas retaining wall; the ampule extending into saidrecesses, impact upon the cap serving to apply breaking force to thefrangible container to release the compressed gas, the released gasbeing confined within the enclosure means to act against the striker,whereby the striker is propelled by the gas to strike upon thepercussion cap.

10. A non-metallic percussion fuze for land mines comprising: apercussion cap; a firing striker means for the percussion cap includinga gas-propelled piston; a frangible hermetically sealed containercontaining a propellant consisting of compressed gas; the striker meansbeing positioned between said container and the percussion cap;enclosure means surrounding said sealed container and said strikermeans; said enclosure means providing a base, an impact cap, and alateral wall conmeeting the base and impact cap, impact upon the capserving to apply breaking force to the frangible container to releasethe compressed gas, the released gas being confined within the enclosuremeans and against the piston of striker means, whereby the striker meansis propelled to strike upon the percussion cap.

11. A springless non-metallic percussion fuze for land mines comprisinga percussion cap, a firing striker means for the percussion cap, saidstriker means including a gas-propellable piston; a frangiblehermetically sealed container containing compressed gas, the strikermeans being positioned between said container and the percussion cap;enclosure means surrounding said sealed container and said strikermeans, said enclosure means providing a base. structure carrying thepercussion cap, an impact cap, and a lateral wall connecting the cap andbase structure; the impact cap being spaced from the base structure bysaid wall, the cap and base structure each having recesses, the sealedcontainer extending into said recesses, the piston of the striker meansbeing positioned in the recess of the base structure, the lateral wallyielding upon impact applied to the impact cap, impact upon the capserving to apply breaking force to the frangible container to releasethe compressed gas, the released gas being confined within the enclosuremeans and against the piston of the striker means, whereby the strikermeans. is propelled to strike upon the percussion cap.

12. A non-metallic percussion fuze for land mines comprising apercussion cap, a firing striker for the percussion cap, a frangiblehermetically sealed container containing a pre-fill of compressedpropellant gas, the striker being positioned between said container andthe percussion cap, enclosure means surrounding said sealed containerand said striker, said enclosure means providing a base structurecarrying the percussion cap, an impact cap, and a lateral distortablesealing band connecting the base structure and the impact cap in spacedrelation, impact upon the cap serving to distort the band and permit themovement of the impact cap with respect to the base structure, to'applybreaking force to the frangible container to release the compressed gas,the released gas being confined within the enclosure means and actingagainst the striker, whereby the striker is propelled by the force ofthe gas to strike upon the percussion cap.

References Cited in the file of this patent UNITED STATES PATENTS134,048 Giffard Dec. 17, 1872 1,153,502 Kreigsheim Sept. 14, 19152,004,243 Hlock June 11, 1935 2,377,174 Parker May 29, 1945 2,398,718Rasmussen Apr. 16, 1946 2,464,650 Pass et al. Mar. 15, 1949 2,558,756Jackson July 3, 1951 2,695,743 Wetherby-Williams Nov. 30, 1954 2,719,660Ellis Oct.. 4, 1955 FOREiGN PATENTS 37,697 Germany Nov. 20, 1886 694,402France Sept. 15, 1930

